Chuck



E. E. DAVIS CHUCK Filed July l, 1938 1%" yf u, y@

INVENTOR, WHW E. Dgw

e A-WTORNEY,

Patented Oct. 31, 1939 UNITED STATES PATENT OFFIQE CHUCK Emery E. Davis, Glendale, Calif., assigner to Otto H. Siewek, Ferndale, Mich.

Application July 1, 1938, Serial No. 216,902

6 claims. (ci. 279-49) My invention relates to a new and useful iming radially directing slot It and with axially provement in a chuck used for holding and driV- extending grooves Il formed in its periphery, the ing various types of cutting tools having Shanks construction being such that the collet or bushand particularly Shanks circular in cross-section. ing I5 may be sprung inwardly to smaller di- 5 It is an object of the present invention to mensions, this collet or'bushing I5 being formed provide a chuck of this class so constructed and from several resilient material for this purarranged as to effect a tighter gripping on the pose. The periphery of the inner end or the tool shank, maintain a true alignment of the tapered end collet or bushing I5 is cut away to tool shank with the driving arbor and effect a provide the inclined inner-end surface i9 and 1() concentric operation on the work-piece upon a similar-cutting away of the outer end is effected 10 which operated. to provide the inclined outer surface 25. The in Another object of the invention is the prooline of the surface I9 corresponds to the invision of the shank so arranged and constructed elined surface end 2? of the plug Iii as does likethat a tool shank may be very easily andquickwise the inclined surface of the shoulder I3. This l5 ly secured in position and released therefrom. Shoulder prevents the plug lll from falling in- 15 Other objects will appear hereinafter. wardly through the Openings i2 When pleed The invention consists vin the combination and therein. f arrangement of the parts` hereinafter described A collar 2| is threadable onto head i8. This and C1amedcollar 2 I, having adjacent at its rear or inner Re The invention will be best understood by a refend, a groove 22 formed in inner surface, one side 20 erence to the accompanying drawing which forms of said groeve heVing the inclined faCe 23 and .a part of this specication and in which; the collar 2l terminating in an inclined end face Fig. 1 isa longitudinal sectional view of the in- 24 Corresponding t0 the incline Of the end Sur- 'vention face 25 on the plug if The collar 2l is pro- Fig. 2 is a sectional View taken on line 2 2 of vided on its-outer end with an inwardly di- 25 Fig. 1. rected flange 2l terminating in a tapered surface Fig. 3 is a sectional View taken on 1ine 3-3 28 Corresponding in ensularity te the tapered of Fig. l. surface 26.

Fig. 4 is a fragmentary sectiona1 view illus- The device is used for retaining a i001 Sli in 3o trated in parts in the position of being assem- DOSitOn, thiS tOOl 39 being fOmel Circular in 30 bled. cross-section. In securing the tcol 3Q on the Figisafragmentary sectional View similar to holder, the tool 30 should be inserted in the Fig. 4 showing the parts in position 0f further bushing or collet I5 and this should be inserted assembly. in the head I0 as shown in Fig. e. The collar El 35 Fig. 6 is a fragmentary side-elevational view would then be threaded on the head it and as it 35 of the holder. threads on the head lll, the inclined surface 23 of As shown in the drawing I provide a holder the flange 2l Would engage the inclined end surwhich may be secured to a rotating arbor and face 25 of collet or bushing i5 and force the same which provides a hollow head I0, having a tainwardly of the head te. The outside diameter 4,0 pered inner surface I. The periphery of this 0f the COllet 0l bushing i5 iS Slightli7 larger than 40 head I6 is threaded and formed in the head at the the inside diameter of head iii so that as the rear of the head is a plurality of circumferentialeOllet 01 bushing i5 mOi/GS inwardly in the head ly spaced openings I2, these openings being unilll, the bushing or collet l5 would be sprung into forrnly distributed about the center of the head Clamping engagement With the tOOl Sil and Serve 45 ic eo that a rotative balance or the head may t0 Securely grip it. AS the threading ef the C01- e5 be maintained. The openings I2 terminate at lar 2l is proceeded with, the surface 2li would entheir inner ends on a shoulder I3 and positioned gage the end Surface 25 Of the plllgS i4 and OICe in each of these openings I2 is a loose radially these plugs inWal'dly against the ShOulder 0r seat movable plug Iii having its opposite ends tapered. i3 thus permitting the collar 2| to ride over the 5,9 A gripping bushing or collet I5 having a peplugs lil and bring the groove or recess 22 into 50 riphery taper corresponding substantially to the registration with these plugs le. As the groove taper of the surface It is insertable in the head 22 moves inte registration with plugs le, the inlll. This bushing or collet I5 has a cylindrical clined surface IS of the bushing or collet I5 bore il formed therethrough. This collet or would engage the inner end surface 2@ of the .55 bushing I5 is provided with an axially extendplugs I4 and force them outwardly into the 55 recess or groove 22 as shown in Fig. 1 and when this stage is arrived at, the butt of the tool 30 would be securely clamped in position. It will be noted that the periphery of the bushing or collet I 5 is engaged throughout its length with the inclined surface I', thus presenting maximum area of contact for effecting the squeezing operation on the collet or bushing and thus producing a maximum gripping thrust on the tool shank or butt engaged by the collet or bushing I5. It is believed obvious that the size of the crossing threads on the head and collar 2| may be varied to suit various conditions. It is also believed obvious that the tapered surface I0 and the tapered periphery of the collet or bushing I5 may be varied to suit different conditions. By having this pressure exerted uniformly circumferentially to the bushing or collet I5 a proper and true alignment of the tool in the head I0 is effected. By having the plugs I4 uniformly distributed circumferentially, the rotative balance of the head I0 is not destroyed.

One of the difliculties of a holder of this class is the removal of the tool therefrom when it is desired to change the tool. With the present invention, when it is desired to remove the tool, it is but necessary to unthread the collar 2l from the head I0. As this unthreading operation proceeds, the inclined surface 23 will engage the inclined end surface 25 of the plugs I4 and force the same radially inwardly. As these plugs move radially inwardly, the inclined inner end surface 20 of the plugs I4 will, through their engagement with the inner inclined end surface I9 of the collet or bushing I5, force this collet or bushing axially outwardly so that the automatic removal of the tool is effected upon the unthreading of the collar 2I.

It is believed obvious that with the same head and collar various bushings l5 may be used for different sized bores II so that this head provides a maximum range of use.

The efficiency and compactness of the device will appear obvious.

While I have illustrated and described the preferred form of construction I do not wish to limit myself to the precise details of structure shown but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention what I claim as new is:

1. A device of the class described comprising a holder having a tapered bore formed in one end thereof and provided with an opening extending from its periphery into said bore; a split tapered bushing inserted into said bore, the forcing of said bushing inwardly of said bore effecting a contraction of said bushing for clamping a tool inserted therein; a member threaded on said holder and movable axially thereof upon being rotated relatively thereto; a thrust member mounted in said opening and engageable with the inner end of said bushing and adapted of threading upon said threaded member in one direction for moving inwardly of said opening against the inner end of said bushing and forcing the same outwardly of said bore.

2. A device of the class described comprising a holder having a tapered bore formed in one end thereof; a tapered split bushing insertable into said bore, said bushing upon movement inwardly into said bore being compressed for inserting a tool therein, said holder having openings extending from its periphery into said bore; a thrust member slidably mounted in each of said openings and having curvilinear surface on opposite ends and engageable on its inner end with the inner end of said bushing and adapted upon being thrust inwardly while in engagement with the inner end of said bushing for forcing said bushing outwardly into said bore; and means rotatably mounted on and axially movable of said holder for engaging the outer side of said thrust members and forcing the same inwardly for effecting movement of said bushing outwardly of said bore.

3. A device of the class described comprising a. holder having a tapered bore at one end and provided with a plurality of circumferentially spaced openings communicating with said bore; a thrust member loosely positioned in each of said openings, and having curvilinear opposite ends; a split tapered bushing insertable into said bore, the taper on said bushing coinciding with the taper of said bore, said bushing being slightly larger in diameter than said bore and being compressed upon movement inwardly into said bore for clamping a tool in said bushing, the inner end of said bushing, upon being thrust fully into said bore, moving said thrust members outwardly; a collar threadable on said end of said holder and having on its inner surface adjacent its inner end a groove for accommodating the outwardly projecting portions of said thrust members, said groove having an inclined surface on its rear side adapted upon the unthreading of said collar for engaging said thrust members and thrusting the same inwardly for effecting a movement of said bushing outwardly of said bore.

4. A device of the class described comprising a holder having a tapered bore at one end and provided with a plurality of circumferentially spaced openings communicating with said bore; a thrust member loosely positioned in each of said openings, and having curvilinear opposite ends; a split tapered bushing insertable into said bore, the taper on said bushing coinciding with the taper of said bore, said bushing being slightly larger in diameter than said bore and being compressed upon movement inwardly in said bore for clamping a tool into said bushing, the inner end of said bushing, upon being thrust fully into said bore, moving said thrust members outwardly; a collar threadable on said end of said holder and having on its inner surface, adjacent its inner end, a groove for accommodating the outwardly projecting portions of said thrust members, said groove having an inclined surface on its rear side adapted upon the unthreading of said collar for engaging said thrust members and thrusting the same inwardly for effecting a movement of said bushing outwardly of said bore; and means on said collar, engageable with the forward end of said bushing and adapted upon the threading of said collar onto said holder, for forcing said bushing inwardly of said bore.

5. A device of the class described comprising a holder having a tapered bore at one end and provided with a plurality of circumferentially spaced openings communicating with said bore; a shoulder overlying the inner end of said openings; a thrust member loosely positioned in each of said openings and engageable with said shoulder, said shoulder limiting the movement of said thrust member inwardly of said bore, said thrust members having curvilinear spaced sides; a split bushing having a tapered periphery corresponding substantially to the taper of said bore, and insertable into said bore, said bushing being of slightly larger dimensions than said bore and compressible, upon movement inwardly of said bore, for clamping a tool inserted into said bushing, the inner end of said bushing having an inclined surface engageable with the curvilinear surface of said thrust members and adapted, upon completion of the inward movement of said bushing relatively to said bore, for forcing said thrust members outwardly to project beyond the periphery of said holder; a collar threadable on said holder and having inclined surfaces, adapted upon engagement with said thrust members, for moving the same inwardly, said collar having on its inner surface adjacent one of its ends a circumferential groove for accommodating said thrust members upon projection of the same outwardly beyond the periphery of said holder, said groove having an inclined surface adapted, upon the unthreading of said collar from said holder, for engaging the curvilinear outer surfaces of said thrust members for forcing the same radially inwardly and eifeoting movement of said bushing outwardly of said bore.

6. A device of the class described comprising a holder having a tapered bore at one end and provided with a plurality of circumferentially spaced openings communicating with said bore; a shoulder overlying the inner end of said openings; a thrust member loosely positioned in each of said openings and engageable with said shoulder, said shoulder limiting the movement of said thrust member inwardly of said bore, said thrust mein:

bers having curvilinear spaced sides; a split bushing having a tapered periphery corresponding substantially to the taper of said bore and insertable into said bore said bushing being of slightly larger dimensions than said bore and compressible upon movement inwardly of said bore for clamping a tool inserted into said bushing, the inner end of said bushing having an inclined surface engageable with the curvilinear surface of said thrust members and adapted, upon completion of the inward movement of said bushing relatively to said bore, for forcing said thrust members outwardly to project beyond the periphery of said holder; a collar threadable on said holder and having inclined surfaces adapted upon engagement with said thrust members, for moving the same inwardly, said collar having one its inner surface adjacent on end a circumferential groove for accommodating said thrust mem,- bers upon projection of the same outwardly beyond the periphery of said holder, said groove having an inclined surface adapted, `upon the unthreading of said collar from said holder for engaging the curvilinear outer surfaces of said thrust members for forcing the same radially inf wardly and effecting movement of said bushing outwardly of said bore; and an engagement means carried by said collar and engageable with the outer end of said bushing and, upon threading of said collar on said holder, effecting movement of said bushing inwardly of said bore.

EMERY E- DAVIS,z 

